Determining the degree of chromosomal instability in breast cancer cells by atomic force microscopy.

Chromosomal instability (CIN) is a source of genetic variation and is highly linked to the malignance of cancer. Determining the degree of CIN is necessary for understanding the role that it plays in tumor development. There is currently a lack of research on high-resolution characterization of CIN and the relationship between CIN and cell mechanics. Here, a method to determine CIN of breast cancer cells by high resolution imaging with atomic force microscopy (AFM) is explored. The numerical and structural changes of chromosomes in human breast cells (MCF-10A), moderately malignant breast cells (MCF-7) and highly malignant breast cells (MDA-MB-231) were observed and analyzed by AFM. Meanwhile, the nuclei, cytoskeleton and cell mechanics of the three kinds of cells were also investigated. The results showed the differences in CIN between the benign and cancer cells. Also, the degree of structural CIN increased with enhanced malignancy of cancer cells. This was also demonstrated by calculating the probability of micronucleus formation in these three kinds of cells. Meanwhile, we found that the area of the nucleus was related to the number of chromosomes in the nucleus. In addition, reduced or even aggregated actin fibers led to decreased elasticities in MCF-7 and MDA-MB-231 cells. It was found that the rearrangement of actin fibers would affect the nucleus, and then lead to wrong mitosis and CIN. Using AFM to detect chromosomal changes in cells with different malignancy degrees provides a new detection method for the study of cell carcinogenesis with a perspective for targeted therapy of cancer.

Cell recognition based on atomic force microscopy and modified residual neural network.

Cell recognition methods are in high demand in cell biology and medicine, and the method based on atomic force microscopy (AFM) shows a great value in application. The difference in mechanical properties or morphology of cells has been frequently used to detect whether cells are cancerous, but this detection method cannot be a general means for cancer cell detection, and the traditional artificial feature extraction method also has its limitations. In this work, we proposed an analytic method based on the physical properties of cells and deep learning method for recognizing cell types. The residual neural network used for recognition was modified by multi-scale convolutional fusion, attention mechanism and depthwise separable convolution, so as to optimize feature extraction and reduce operation costs. In the method, the collected cells were imaged by AFM, and the processed images were analyzed by the optimized convolutional neural network. The recognition results of two groups of cells (HL-7702 and SMMC-7721, SGC-7901 and GES-1) by this method show that the recognition rate of dataset with the combination of cell surface morphology, adhesion and Young's modulus is higher, and the recognition rate of the dataset with optimal resolution is higher. Our study indicated that the recognition of physical properties of cells using deep learning technology can serve as a universal and effective method for the automated analysis of cell information.

Comparison of Pull and Introducer Techniques for Percutaneous Endoscopic Gastrostomy.

Objective: To compare indications, success rates and complications of pull [P] and introducer [I] techniques for percutaneous endoscopic gastrostomy (PEG). Methods: In this retrospective study, inpatients who underwent primary PEG tube insertion between January 2015 and February 2020 at the Endoscopy Center of the First Affiliated Hospital of Fujian Medical University were included. Results: A total of 103 inpatients were included in this study (P group, n = 67; I group, n = 36). The rates of tube replacement within first six months in the P and I groups were 1.5% and 11.1%, respectively (P = 0.049). The most common primary indication of PEG was malignancy. The proportion of patients with esophageal cancer was significantly lower in the P group (24.4% vs 54.2%, P = 0.015). No significant difference was found in the overall, major, or minor complications between the two groups. In patients with esophageal stenosis, the pull method was a risk factor for complications (P = 0.03; odds ratio [OR] = 12, 95% confidence interval [CI]: 1.164-123.684). Logistic regression analysis showed that the risk factors for major and minor complications were the admission-to-gastrostomy interval (OR = 1.078, 95% CI: 1.016-1.145, P = 0.014) and lack of antibiotic use (OR = 4.735, 95% CI: 1.247-17.979, P = 0.022), respectively. Conclusion: Both PEG techniques have high clinical success rates. The introducer technique is more suitable for patients with esophageal stricture, which has lower minor complications, but higher rate of tube replacement compared to the pull technique. Use of antibiotics may reduce minor complications following PEG. Early PEG insertion may help to reduce post-PEG major complications.

Quasi-2D Growth of Aluminum Nitride Film on Graphene for Boosting Deep Ultraviolet Light-Emitting Diodes.

Efficient and low-cost production of high-quality aluminum nitride (AlN) films during heteroepitaxy is the key for the development of deep ultraviolet light-emitting diodes (DUV-LEDs). Here, the quasi-2D growth of high-quality AlN film with low strain and low dislocation density on graphene (Gr) is presented and a high-performance 272 nm DUV-LED is demonstrated. Guided by first-principles calculations, it is found that AlN grown on Gr prefers lateral growth both energetically and kinetically, thereby resulting in a Gr-driven quasi-2D growth mode. The strong lateral growth mode enables most of dislocations to annihilate each other at the AlN/Gr interface, and therefore the AlN epilayer can quickly coalesce and flatten the nanopatterned sapphire substrate. Based on the high quality and low strain of AlN film grown on Gr, the as-fabricated 272 nm DUV-LED shows a 22% enhancement of output power than that with low-temperature AlN buffer, following a negligible wavelength shift under high current. This facile strategy opens a pathway to drastically improve the performance of DUV-LEDs.

Ultraviolet to mid-infrared supercontinuum generation in single-crystalline aluminum nitride waveguides.

We demonstrate ultrabroadband supercontinuum generation from ultraviolet to mid-infrared wavelengths in single-crystalline aluminum nitride waveguides. Tunable dispersive waves are observed at the mid-infrared regime by precisely controlling the waveguide widths. In addition, ultraviolet light is generated through cascaded second-harmonic generation in the modal phase-matched waveguides. Numerical simulation indicates a high degree of coherence of the generated spectrum at around the telecom pump and two dispersive waves. Our results establish a reliable path for multiple octave supercontinuum comb generation in single-crystalline aluminum nitride to enable applications including precision frequency metrology and spectroscopy.

Aluminum nitride-on-sapphire platform for integrated high-Q microresonators.

We demonstrate aluminum nitride (AlN) on sapphire as a novel platform for integrated optics. High-confinement AlN microring resonators are realized by adopting a partially etched (pedestal) waveguide to relax the required etching selectivity for exact pattern transfer. A wide taper is employed at the chip end facets to ensure a low fiber-to-chip coupling loss of ~2.8 dB/facet for both transverse-electric (TE) and transverse-magnetic (TM) modes. Furthermore, the intrinsic quality factors (Qint) recorded with a high-resolution linewidth measurement are up to ~2.5 and 1.9 million at telecom band for fundamental TE00 and TM00 modes, corresponding to a low intracavity propagation loss of ~0.14 and 0.2 dB/cm as well as high resonant buildup of 473 and 327, respectively. Such high-Q AlN-on-sapphire microresonators are believed to be very promising for on-chip nonlinear optics.

The role of primary surgical treatment in young patients with squamous cell carcinoma of the larynx: a 20-year review of 34 cases.

BACKGROUND: The aim of this study was to investigate the clinical patterns in young Chinese patients (less than 40 years old) with laryngeal squamous cell cancer (LSCC) and the outcome of primary open surgery. METHODS: Thirty-four young patients, with histologically confirmed LSCC between 1985 and 2005 at Qilu Hospital and Affiliated Hospital of Weifang Medical College, who underwent primary open surgery were retrospectively evaluated according to the clinical patterns in comparison with 374 non-young patients (older than 40 years). The Kaplan-Meier method was used to calculate the survival rate. The relevance of smoking, tumor location, tumor-node-metastasis (TNM) staging, lymph node involvement, tumor size, and histological differentiation to overall survival was tested by multivariate analysis. RESULTS: There was a significantly higher rate of smoking (p = 0.020) in the non-young patients compared to the young patients, but no significant difference was observed in alcohol consumption, tumor location, tumor size, TNM staging, lymph node metastasis, histological grade, and 5-year overall survival. One-year survival rates were 100%, 3-year survival rates were 79.41%, and 5-year survival rates were 67.65%. In the multivariate analysis, lymph node involvement (p = 0.006), tumor stage (p = 0.022), and tumor size (p = 0.004) proved to be significant predictors of overall survival. CONCLUSIONS: The incidence of smoking was significantly higher in non-young patients compared to young patients. Primary surgery with or without radiotherapy may provide a value treatment option for young LSCC. Nodal status, tumor stage, and tumor size were the primary determinants of overall survival in multivariate analysis. These data may provide useful information for counseling and treatment planning.

G1/S-specific cyclin-D1 might be a prognostic biomarker for patients with laryngeal squamous cell carcinoma.

OBJECTIVE: To investigate the prognostic role of antigen KI-67 (Ki-67) and G1/S-specific cyclin-D1 (cyclin-D1) in patients with laryngeal squamous cell carcinoma (LSCC). METHODS: Immunohistochemical staining (IHS) was used to determine the protein expression of Ki-67 and cyclin-D1 in LSCC tissues. Kaplan-Meier survival curves was calculated with reference to Ki-67 and cyclin-D1 levels. RESULTS: Cyclin-D1 and Ki67 were expressed in the nuclei of cancer cells. Among the total of 92 cancer tissues examined by immunohistochemistry, 60 (65.22%) had cyclin-D1 overexpression and 56 (60.87%) had Ki67 overexpression. Cyclin-D1 overexpression is associated with the advanced stage of the cancer (P=0.029), but not with gender, age, stage of cancer, histological differentiation, anatomical site, smoking history and alcohol consumption history. Ki67 overexpression is not associated with the advanced stage, gender, age, histological differentiation, anatomical site, smoking history and alcohol consumption history. A statistically significant correlation was found between lymph node status and the expression of Ki67 (p=0.025). Overexpression of cyclin-D1 was correlated to shorter relapse-free survival period (P<0.001). CONCLUSIONS: Overexpression of cyclin-D1 can be used as a marker to predict relapse in patients with LSCC after primary curative resection.

Role of centromere protein H and Ki67 in relapse-free survival of patients after primary surgery for hypopharyngeal cancer.

PURPOSE: Centromere protein H (CENP-H) and Ki67 are overexpressed in some malignancies, but whether they are predictors of survival after primary resection for hypopharyngeal squamous cell carcinoma (HSCC) remains unknown. METHODS: We assessed immunohistochemical expression of CENP-H and Ki67 in 112 HSCC specimens collected between March 2003 and March 2005 for analysis by clinical characteristics. The Kaplan-Meier method was used to analyze relapse-free survival and logistic multivariate regression to determine risk factors of relapse-free survival. Cholecystokinin octapeptide assays and flow cytometry were used to examine cell proliferation and apoptosis after siRNA inhibition of CENP-H in HSCC cells. RESULTS: Overall, 50 (44.6%) HSCC specimens showed upregulated CENP-H expression and 69 (61.6%) upregulated Ki67. An increased CENP-H protein level was associated with advanced cancer stage and alcohol history (P=0.012 and P=0.048, respectively) but an increased Ki67 protein level only with advanced cancer stage (P=0.021). Increased CENP-H or Ki67 were associated with short relapse-free survival (P<0.001 or P=0.009, respectively) and were independent predictors of relapse-free survival (P=0.001 and P=0.018, respectively). siRNA knockdown of CENP-H mRNA inhibited cell proliferation and promoted cancer cell apoptosis in vitro. CONCLUSIONS: Upregulated CENP-H and Ki67 levels are significantly associated with short relapse-free survival in HSCC. These factors may be predictors of a relapsing phenotype in HSSC cases.